The present invention relates to a clutch mechanism of a push-button tuner which is compact and flat so as to be adapted for a tape recorder, and more specifically relates to a clutch mechanism having a simple structure and a smooth operations.
Recent market conditions indicate that there may be a considerably big demand for tape recorders provided with a push-button tuner. Naturally, various types of mechanisms designed to meet the demand are now being searched for, which requires a type of tuner having an optimum physical thinness to be compatible with the tape recorders.
The U.S. Pat. No. 4,204,179 describes a push-button tuner which is compact and flat in size designed to be adapted for a tape recorder.
The tuner includes flat slidable cam plates provided with cam portions at the front thereof, which are arranged horizontally and slidably through holes of side walls and a push-button assembly slidably arranged in front and rear walls thereof. The tuner is equipped with a channeling plate pivotable thereon the position of which may be set at a desired angle by means of the operation of a manual shaft when the clutch mechanism is engaged. The clutch mechanism which is operable by the manual shaft comprises various elements such as a clutch lever support, a gear wheel, a disc, a collar, a rotation means and a lever plate etc. With the advancement of the push-button plate against a coil spring arranged at the end thereof, the projections positioned on the channeling plated set at a desired angle collide with the cam portions of the slidable cam plates intermittently whereby the slidable cam plates are shifted transversely and the intermittent shifting movements of the cam plates thus created are transmitted to the foot of a core carriage by turns through a rotation means connected therewith with the result that the cores mounted on the carriage are shiftable back and forth with respect to the coil bodies whereby the variation of inductance is obtained.
The conventional tuner heretofore described has so far succeeded to achieve the object as far as thinness and size thereof is concerned. However, the tuner has complexities in its structure. Especially the clutch mechanism is composed of so many elements as herefore explained. Therefore, the production thereof requires many complicated steps with resultant increase of production costs.
It is an object of this invention to provide a clutch mechanism having a simple structure by reducing the number of component elements and production costs to a minimum.
Another object of this invention is to provide a simple clutch mechanism equipped with a gear wheel and a rotatable means which performs a smooth and accurate clutching or declutching operation of a push-button tuner.
Other and further objects, features and advantages of the invention will appear more fully from the following descriptions.
A brief description of a clutch arrangement of the present invention will be given hereunder.
When a clutch mechanism is in an engaged state, with the rotation of a main manual shaft, the movement is transmitted through a pair of gears to a follower manual shaft having a worm gear mounted thereon with which a gear wheel within which a rotation means is positioned is meshing whereby the follower manual shaft and the gear wheel rotates accordingly, together with the rotation means. A pair of feet of the rotating means slidably positioned in two sliding cam plates horizontally and slidably supported by a tuner frame shift transversely bringing forth an alternating shifting of the two sliding cam plates. Simultaneously, an arm of said rotation means connected to a core carriage by means of a coil spring causes back or forth movement thereof whereby cores mounted on the core carriage are shifted with respect to coil bodies with the result that the desired variation of inductance is obtained.
The worm gear mounted on the follower manual shaft which is meshing with the gear wheel regardless of the clutch mechanism being engaged or disengaged can be moved away from the gear wheel by a clutch plate shifted by the forward pushing of push-button plate whereby the engagement of the gear wheel with the rotation means is released while the meshing between the worm gear and the gear wheel is still maintained with the result that the disengaged state of the clutch mechanism may be maintained.